Epidemiology the backbone of public health

epidemiology the backbone of Public Health not to be confused with the actual backbone which is often done by dodgy chiropractors so if you are studying epidemiology maybe as part of an mph program and you're finding it more confusing than the latest season of Game of Thrones I don't blame you when I first started studying epidemiology I actually thought that I'd walked into a foreign language class in fact if you're not a little confused and you're probably not paying attention epidemiology often seems like a complex conglomerate of seemingly unconnected ideas again very similar to the latest season of Game of Thrones things like study design of confounding and risk standardization life expectancy attack rates latency period telepathy okay not celebrity Oh should try to make sure that you're paying attention what I'm going to do is I'm going to try and simplify NASA genealogy boil it down to a one sentence definition that's going to give you some context it'll be like a canvas onto which you can hang these various ideas so that when you take a step back and look at the big picture you know exactly how these things fit together welcome back to this global health youtube channel my name is Greg Martin if this is your first time here please consider subscribing I'd love to have you as part of this community of like-minded people who want to make the world a better safer healthier place now let me start by saying this if you're working or you want to work in public health and you absolutely have to have at least a basic understanding of epidemiology so epidemiology really revolves around trying to measure two things distribution and causation and we're going to take a closer look at ETV in just a moment but first a big thank you to the University of Maryland graduate school for their support the University of Maryland graduate school offer a fantastic online global health certificate which if you want to study further can be applied to an online master's degree in health sciences so if you're wanting to study global health but you can't take the time off work to attend a full time course then this is a really good option for you click on the link in the description below to find out more now let's talk about epidemiology we're going to start off by talking about this idea of distribution we're interested in how various diseases or other states of health we could be looking at a health improvement for example how these things are distributed in society so if for example we're interested in fusion of HIV let's take a look at what that means well we're interested in who has HIV where for the key they are and how that might be changing over time in other words we're interested in the demographic the geographic and the temporal distribution of HIV and society demographics so these are these people old people young people rich people poor people males females people who do and people who do not understand all the references are making to Game of Thrones so we're really interested in this broader definition of social demography any parameter that will help us understand the different sections of society Geographic well that's pretty self-explanatory it's where physically these diseases or various states of health might be and temporal and here we're interested in how the incidence and prevalence of a disease is changing over time so firstly we're interested in the distribution of diseases and other states of health and we call these outcomes that we're also interested in the distribution of exposures and these are anything that may cause or prevent disease in the community now exposures could be environmental hazards things like severe weather events meteorological events like an earthquake or water and air pollution or exposure to chemical radiological or infectious – these agents or exposure to social determinants of health things like conflict gender inequity and poverty and exposures can be things like public health interventions like tobacco taxation or the provision of medicines or vaccines to treat or prevent diseases and of course these kinds of exposures improve health and again in this group we've got the social determinants of health things like education employment the protection of human rights all of these things translate into an improvement of health as an individual and population level and this brings us very neatly to the second issue that occupies the minds of epidemiologists and that is the issue of causation and here we're thinking about the extent to which these exposures really do or do not genuinely translate into changes in outcomes or the health status of people and populations so let's talk about causation for just a minute because it's really important when we see a correlation between two things as one thing goes up another thing goes up as well we often incorrectly make the assumption that there's a causative relationship between these two variables now that's really bad science and believe me this happens a lot so for example does eating ice cream increase your chances of being attacked by a shark of course there's a strong correlation between ice cream eating and shark attacks because what's both of these things happen to happen on hot days in summer that eating ice cream of course doesn't cause shark attacks is a confounding variable which is an alternative explanation associated with both the exposure and the outcomes and in this case it's hot weather now don't ask me about people who swim in the sea and eat ice cream at the same time that's just showing off and you're offering the shark both a meal and dessert at the same time you're asking for trouble and there's quite a few other things that you need to think about when you see a correlation between two variables before you make the assumption that there's a causative relationship and these include things like confounding that we've just talked about but also bias error chance reverse causation key hacking and fraud amongst others and you can take a look at the bread food Hill criteria which incidentally even according to Hill should not be used as a checklist but I'm not going to get into that in this video I'm going to create other videos and I have in fact created other videos that look at many of these things take a look at them if you're interested but for now what I want you to take away is a nice neat definition of Epidemiology so epidemiology is the science that considers the demographic the geographic and the temporal distribution of exposures and outcomes and the causative relationship between them my channel has got a playlist that builds just with epidemiology if you're interested so check that out if you want to watch more thanks so much to all of those that support this channel at patreon.com I really appreciate it couldn't do it without you and of course a big thank you to the University of Maryland for their support click on the link in the description below to find out more about their programs thanks for watching you


  1. the night king must probably be coming for you…

  2. You are awesome Mr. Martin!

  3. Thank you for sharing

  4. Thank you for making this video. It has given me some picture about what epidemiology is all about 😀

  5. I am accusing Health Organisations of (intentionall??) neglect. I will change mind if a scientist give me logical arguments against.
    A FATAL HYGIENE-MEDICAL MISTAKE CAUSES ACQUIRED HOSPITAL INFECTIONS and UTIs. Wiping, no matter its direction, is, in anyway, dangerous, particularly to women. Τhe DUST that comes from the feces film left after wiping, full of microbes, THROUGH DRYING, FRICTION and AIR, travels to the near uro-genital organs, causing UTI and later to the air and any surface of the house or worse of the HOSPITAL, in the case of in hospital patients, causing the often LETHAL ACQUIRED HOSPITAL INFECTIONS. Keep in mind that the in Hospital weakened ill or old patients are not able even to wipe properly, particularly if ΗEMORRHOIDS coexist. If, correctly, the dust during construction works in Hospitals, is thought as dangerous for its microbes, it is so obviously contradictory, that the dust coming from dried feces, is not!! WHO and Drs it is urgent to take some action, as patients and staff are on every day danger . Zisis Kontogounis, retired Medical Dr.

  6. Dr. Martin, thank you for this content! Your knowledge and ability to explain and contextualize complex ideas is amazing.

  7. I am interesting to become epidemiologist. Thank you for your good presentation. It's well attractive.

  8. sir ,,Your video is more educative and easy for beginner of programming .Please add more lecture on c++

  9. Thank you so much DR Please i will like you to advise me on how to overcome my difficulties in epidemiology

  10. very imressive!

  11. this video is catering to those who are very left brained and want mainstream science

  12. Hey, why the cut on the Chiropractors? Why we got to be dividing the ways of health and healing. Lets build bridges, rather than divide. Without faith, the body can't be healed. Faith is a starting point for all things. Come on Greg… 😉 said with much love and respect… -Aharon W Smith


  14. Wow keep it up you are doing such a good job

  15. very helpful though you speak quickly

  16. Wow! Cheers Dr, I really love your lessons so i hope others

  17. hello Dr. martin ..
    thank you for this video and I want more information about confunding ..
    and thank you

  18. I am now taking public health my love, but this topic is confusing

  19. I like this channel , I like the way you summarize the topic ..
    Thank you …

  20. I love your videos!! Thanks a lot 😀

  21. Hello Dr. Martin. Thanks for your video about Epi. I'm the first one in my community and family to be in PH and Epi so I was looking for a video to share with my professional social justice network, community, and friends/family. This video has great graphics. It has a great goal to cover the basic of Epi. Some feedback are that the speaker's speed is quite fast so I used closed captioning. I understood the concepts mentioned however I've completed biostats, epidemiology, advanced epi, etc. while I've been working on my MPH-MPHP with a focus on epidemiology. I would recommend attempting to break this video apart or simplify because it covers quite a lot. It could potentially be a summary for new students as they start their first epi course however there are quite a lot of terms that may soar over their heads. Finally, I was confused with the divisions in the video. I'll watch again however I believe I heard three sections: 1) intro, 2) advertisement for Univ. of Maryland, and 3) intro then epi review. The large section on Univ. of Maryland seems very out of place and confusing in this place as well as added a chunk of time that I found detracting from the goal. Overall, I thought it was a good start but I would not (at this point) really recommend it to my fellow epi students nor to students I meet along the way who are thinking of taking epi or focusing on the subject. I wish you the best and will explore your other videos.

  22. Hi Dr Martin…great work as ever! I sent you a question via twih website and hope you received it? please do let me know. best

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